"""
打印正直角三角
*
**
***
****
*****
i = 1
while i<=5:
    print("*"*i)
    i += 1

"""

"""
打印倒直角三角
*****
****
***
**
*
"""
i = 5
while i>=1:
    print("*"*i)
    i -= 1

# 外层循环
i = 0
while i < 5:
    # 内层循环
    j = 0
    while j < 3:
        print(j)
        j += 1
    i += 1